This article is from the ECONOS part of the joint special issue on the European Conference on Nonlinear Optical Spectroscopy (ECONOS 2012) with Guest Editors Johannes Kiefer and Peter Radi and the II Italian Conference of the National Group of Raman Spectroscopy and Non-Linear Effects (GISR 2012) with Guest Editor Maria Grazia Giorgini.
Time-resolved femtosecond CARS from 10 to 50 Bar: collisional sensitivity†
Article first published online: 26 MAR 2013
Copyright © 2013 John Wiley & Sons, Ltd.
Journal of Raman Spectroscopy
Special Issue: Joint special issue on the European Conference on Nonlinear Optical Spectroscopy (ECONOS 2012) and the II Italian Conference of the National Group of Raman Spectroscopy and Non-Linear Effects (GISR 2012)
Volume 44, Issue 10, pages 1344–1348, October 2013
How to Cite
Wrzesinski, P. J., Stauffer, H. U., Kulatilaka, W. D., Gord, J. R. and Roy, S. (2013), Time-resolved femtosecond CARS from 10 to 50 Bar: collisional sensitivity. J. Raman Spectrosc., 44: 1344–1348. doi: 10.1002/jrs.4287
- Issue published online: 22 OCT 2013
- Article first published online: 26 MAR 2013
- Manuscript Accepted: 12 FEB 2013
- Manuscript Revised: 6 FEB 2013
- Manuscript Received: 21 NOV 2012
- AFRL. Grant Number: FA8650-12-C-2200
Femtosecond time-resolved coherent anti-Stokes Raman scattering (CARS) measurements are performed on neat N2 and O2 as well as on N2 in the presence of various collisional partners to examine the effects of collisions on the observed signal at pressures as high as 50 bar. An exponential-gap energy-corrected-sudden (ECS-E) scaling law is used to model the rotational energy transfer of pure N2 at these elevated pressures. After accounting for line-mixing effects, the long-time collisional decay (20–60 picoseconds behavior observed here is consistent with the behavior observed in previous time-resolved CARS studies over the pressure range 0–5 bar. Despite the observation of significant pressure dependence on long-delay timescales, the experimental results demonstrate negligible dependence on pressure and identity of colliding partner during the first 1–3 picoseconds, a time range that has been shown previously to be highly sensitive to temperature. These results suggest that a variety of recently developed time-resolved CARS approaches that allow accurate thermometric measurements to be made over this short 1–3 picosecond range can be used at pressures up to 50 bar without the need to employ models accounting for collisional decay. Copyright © 2013 John Wiley & Sons, Ltd.